How and When to Cut Ornamental Grasses

Ornamental grass / Poaceae evergreen perennial Stipa tenuissima(Angel hair).

Generally, most ornamental grasses should be cut in spring or fall, depending on what type they are. Let’s go over the specifics of how and when to cut ornamental grasses.

Ornamental grasses aren’t the same as the turf on your lawn. They aren’t cut weekly, but rather yearly (or every few years).

What are ornamental grasses?

Ornamental grasses are a group of grasses and grass-like plants that are used as landscape plants. In contrast to turf, ornamental grasses are allowed to grow long because their leaves, stems, and flowers are aesthetically pleasing and add visual interest to a yard. 

Ornamental grasses are also typically easy to care for, needing little maintenance compared to turf.

Many ornamental grasses are perennial, but there are a few annual grasses that are grown as ornamentals. Some of these annuals include annual fountain grass, dwarf pampas grass, and ornamental millet. These require yearly replacement as they die after one year.

When to cut ornamental grasses

closeup of feather reed grass
Feather reed grass
Drew Avery | Flickr | CC BY 2.0

Knowing when to cut ornamental grasses starts with figuring out what type of grass they are, as they’re cut at different times of the year. Ornamental grasses can be divided into cool-season, warm-season, and evergreen.

A general rule is that it’s best to cut your ornamental grasses before the start of their active growing season or just after they’ve gone dormant

You can also cut your grasses in winter after they’ve gone dormant, but many ornamental grasses look beautiful and add winter interest during an otherwise dull season. They provide color, volume, and movement (from the wind).

Note that these rules apply to perennial grasses, not annuals. Annual grasses die after one year and will need to be removed — roots and all — once they die. 

Let’s go over when to cut the different types of ornamental grasses.

When to cut cool-season ornamental grasses

It’s best to cut cool-season ornamental grasses in very early spring or late winter before they start flowering and growing again. You don’t want to damage the new shoots and flowers.

Similar to cool-season turfgrasses, cool-season ornamental grasses grow most actively during the spring, fall, and winter when the temps are 65 to 75 degrees Fahrenheit. Then, they bloom in spring or early summer. Cool-season ornamental grasses go dormant in summer. 

Some cool-season ornamental grasses include the following. Many of these are native grasses according to the Colorado State University Extension.

  • Blue fescue and other fescue grasses
  • Feather reed grass
  • Autumn moor grass
  • Indian ricegrass
  • Sand love grass
  • Blue oat grass
  • June grass
  • Silky thread grass
  • Tufted hair grass
  • Velvet grass
  • Blue lyme grass

Pro tip: Growing native grasses saves you money on fertilizer, water, and pesticides. There are other benefits that you can read about here: 12 Reasons You Should Grow Native Plants.

When cutting cool-season ornamental grasses, cut back two-thirds of the plant, leaving the last one-third intact.

When to cut warm-season ornamental grasses

Ornamental grass: Poaceae, Beatuiful tender fountain grass
Dinesh Valke | Flickr | CC BY-SA 2.0

The best time to cut back warm-season ornamental grasses is during mid to late spring, with areas with warmer temperatures cutting earlier.

Like warm-season turfgrasses, warm-season ornamental grasses also have active growing seasons in late spring through summer. They bloom as early as mid-summer up to as late as early fall.

Many warm-season ornamental grasses grow dormant during the cooler temperatures of fall and wake up in spring. While you could cut your grass back in winter, many warm-season grasses have beautiful brown and burgundy hues that can add winter interest.

Some warm-season ornamental grasses include the following. Many of them are also native to the U.S.:

  • Switchgrass
  • Little bluestem
  • Big bluestem
  • Fountain grass
  • Hakone grass
  • Japanese silver grass and other silver grasses
  • Side oats grama
  • Blue grama
  • Indian grass
  • Prairie dropseed
  • Pampas grass

When cutting back warm-season ornamental grasses, cut away most of the plant. Leave around 3 to 6 inches of the plant above the ground (depending on size).

When to cut evergreen ornamental grasses

You shouldn’t cut most evergreen grasses unless absolutely necessary, like if it’s especially unkempt. At most, you should only prune the oldest or most damaged leaves in early spring. You can also cut off the tips and flowerheads that look unruly as needed.

Some ornamental grasses are evergreen, never growing dormant. Most evergreen ornamental grasses are actually not grasses at all; instead, they are grass-like plants like sedges and rushes.

Unlike true grasses, many grass-like ornamental plants can’t handle being cut back. Refrain from cutting them back more than once every two to three years.

Instead, the Clemson University Cooperative Extension Service and other experts recommend that homeowners comb through the foliage of evergreen grasses while wearing rubber gloves. The dead leaves will stick to your gloved hands in clumps.

How to cut ornamental grasses

Close up of grown ornamental grass

Cutting ornamental grasses is quite easy and straightforward, if only a bit messy. You may also encounter difficulty if the grass is quite large or thick.

Tools and materials

Here are the following tools and materials you will need to complete this project:

  • A cutting tool
    • Pruning shears
    • Power hedge trimmer
    • Weed whacker
    • Handheld scythe
    • Chainsaw (only for very tough grasses, not recommended otherwise)
  • A way to tie up the grass
    • Tape (can be biodegradable)
    • Bungee cords
    • String
  • Protective gear
    • Gloves
    • Long-sleeved shirt
    • Closed-toed shoes
    • Safety goggles
  • Wheelbarrow or tarp
  • Rake

Shears and scythes are more than enough to cut through most ornamental grasses. Only break out the stronger tools if you are having trouble cutting through your grass.

When it comes to tying up your grass, you have many options. Using biodegradable tape means that you don’t have to take the tape off when throwing away or composting your grass. Bungee cords are a reusable option for the eco-conscious.

The protective gear is needed as some grasses have very sharp leaves that can cut you while you’re cutting them. Those grasses can probably poke your eye out too if you’re not careful.

Step 1: Tie up the grass into bundles

First, use your tape, bungee cords, or string to tie your ornamental grass into a bundle.

If your grass is quite long, tie back the grass two to three times along the length of the stem for a neater cut.

Divide your ornamental grass into two or more sections if your grass is wide instead.

While it’s possible to cut the grass while just holding it, it gets very messy very quickly. The messiness can confuse you, plus you might regret how difficult the grass is to clean up.

Step 2: Cut the ornamental grass

Next, it’s time to cut back the grass. Cut the grass according to the type of ornamental grass you have:

  • Cool-season grass: 2/3rds of the plant, leaving 1/3rd of the grass
  • Warm-season grass: Down to the ground, leaving only 3 to 6 inches of the grass

As you cut, push the bundle of grass back so that it’s leaning away from the base. Cut the ornamental grass as evenly as you can while keeping the bundle as intact as possible.

Once you’re done cutting, you should be left with a bundle of grass. There may be some grass leaves that were left behind. Cut those away and keep them with the bundle.

If you’re cutting more grass, place the bundle on a tarp or in a wheelbarrow for easy transportation later.

Step 3: Clean up

When you’re done cutting, take your rake and rake up any loose blades of grass on the ground. 

You should also reach into the grass clump that was left behind and get rid of any loose, matted, or dead leaves and stems.

You have two options for getting rid of your grass bundles: composting and throwing it away, possibly in your local area’s lawn waste dumping site if you can’t dispose of it in the trash.

If you’re composting your grass bundles, we recommend cutting them up into smaller pieces for faster decomposition. 

You also may want to add green materials rich in nitrogen — such as turfgrass clippings, coffee grounds, crushed eggshells, and manure — or a bit of nitrogen fertilizer. This is to even out the ratio of your compost pile. Dry bundles of ornamental grass are carbon-rich and can throw off the balance when you add too much.

Regardless of which method you go with, you’ll need to untie your bundles if you’ve used a non-biodegradable or reusable option.

Why should you cut ornamental grasses?

Beautiful ornamental grass with trees in the background

Cutting ornamental grasses is mainly an aesthetic choice. A mix of green and brown leaves doesn’t look particularly pretty now, does it? The new leaves will eventually hide the brown ones. It also keeps your ornamental grass tidy and aesthetically pleasing. However, cutting does benefit your grass. 

Let’s go over these benefits.

Tells your grass to grow

When done at the proper time, cutting ornamental grass signals it to grow new and fresh foliage. Cutting after winter, for example, helps the grass warm up faster and start growing earlier.

Gets rid of debris

Cutting also provides more space for new shoots to grow unrestrained.

Cristopher Enroth, a horticulture educator with the University of Illinois Urbana-Champaign Extension, says, “[R]emoving that old growth can be useful in getting rid of the debris and mimicking fire that created the vast North American prairies where many of our ornamental grasses developed.”

In a way, ornamental grasses (especially native ones) have gone through cycles of “destruction” and regrowth for centuries. Cutting them back is just another version of this destruction — just safer and more controlled.

Removes flammable material

Speaking of fires, dry and brown grass leaves are highly flammable. Some people “cut back” their grass by burning them; that’s a huge no-no as the fire can spiral out of control.

It’s better to cut back your ornamental grasses as soon as you can if you live in a wildfire-prone area.

Why should I not cut my ornamental grass?

There are actually some reasons why you shouldn’t cut back your ornamental grass — at least, not as early as possible:

  • Provides winter interest. Ornamental grasses can make an otherwise dull yard look interesting during winter. They add color, movement, and texture to your property.
  • Insulates the plant. Leaving the leaves alone protects the ornamental grass from harsh winter temperatures.
  • Houses beneficial insects and animals. The leaves and stems of ornamental grasses provide cover and shelter to many animals. However, really tall and big ornamental grasses like pampas grass also can house dangerous creatures, such as snakes.

FAQ about how and when to cut ornamental grass

Why should I grow ornamental grasses?

Ornamental grasses are some of the best drought-tolerant and low-maintenance alternatives to traditional turfgrass.

You can read more about ornamental grass options for your lawn here:

How is dividing ornamental grass different from cutting?

Dividing ornamental grasses is a wildly different process that has different results and a different reason for doing so. 

Ornamental grass division is the act of breaking up a large plant into smaller clumps that can be replanted as new plants. It’s used to keep ornamental grasses small and manageable; you just get new grasses for free in the process.

When should I divide my ornamental grass?

You can divide your ornamental grass during its active growing season. Usually, this means dividing warm-season grass in spring up to mid-summer and cool-season grass during spring or fall.

Avoid dividing your ornamental grass if it is flowering.

Hire a pro for a neat and beautiful yard

While cutting ornamental grass is relatively straightforward, it can be a messy affair. And if you’re not careful, it may harm the plant and you.

If you don’t want to deal with that mess, why not hire a local professional through Lawn Love? We have gardening pros who can maintain your yard and keep it looking fresh and green. We can also connect you with someone who can clean your yard. All it takes is a few clicks, so why not try it out today?

Main Image Credit: Adobe Stock

Janine Caayao

Janine Caayao has always been fascinated with growing plants, from fruits and veggies to bonsai trees and orchids. Now, she’s interested in urban gardening with her family. She loves finding new tips and tricks to keep their plants thriving.